$ { \left[\begin{array}{rr}{-2} & {0} \\ {0} & {0} \\ {3} & {-2}\end{array}\right]+\left[\begin{array}{rr}{2} & {4} \\ {3} & {3} \\ {0} & {-1}\end{array}\right] = {?} } $
To find the sum of two matrices, add the corresponding items between each matrix. ${\left[\begin{array}{rr}{-2}+{2} & {0}+{4} \\ {0}+{3} & {0}+{3} \\ {3}+{0} & {-2}+{-1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{0} & {4} \\ {3} & {3} \\ {3} & {-3}\end{array}\right]}$